Iranian Journal of Plant Physiology
Volume:13 Issue: 1, Autumn 2023

Water is needed for numerous metabolic functions and its loss can modify all characters of plant life. Acer velutinum is a fast-growing species and significant diffuse-porous hardwood in afforestation and reforestation. However, the impact of water stress on A. velutinum has not yet been studied. In this study, the impacts of water deficit on growth, biomass, leaf area, pigment contents, relative water content, free proline, malondialdehyde, superoxide dismutase, and peroxidase activities were studied to describe the morpho-physiological mechanisms related with their drought resistance. One-year Seedlings were exposed to four drought treatments (100, 75, 50, and 25% of the field capacity). The Drought treatments had negative impacts on A. velutinum growth, biomass, and physiological characteristics, as exhibited by decreased plant height, basal diameter, biomass, relative water content, and pigments level, while Proline, MDA concentration, SOD and POD activities multiplied. Drought increased SLA and LAR at mild and moderate treatment, while decreased SLA and LAR at severe treatment, also the growth declining in aboveground biomass was more than the root under severe treatment, so the Root mass ratio (RMR) and Root: Shoot ratio (R/S) expanded. Our data demonstrate that A. velutinum seedlings have the capacity to adapt to water deficit and can develop some experimental advice for velvet maple afforestation and reforestation.

The greenhouse experiment was performed using ‎Jerusalem cherry affected by gibberellic acid (GA3) in four levels (zero (control), 100, 200, and 400 mg/lit) and three types of consumption (foliar, drip treatment, and foliar + drip treatment) application. The results showed that the reciprocal effect of experimental factors on plant height, lateral shoot length, lateral shoot number, fruit number, root length, root wet weight, stem wet weight, chlorophyll a, chlorophyll b, total chlorophyll, pigment function, chlorophyll index, and resuscitate sugars were significant. Simultaneous application of foliar spray and soil consumption + GA3 increased carotenoid and leaf area ratio compared to the use of each treatment alone. According to the comparison of means, the highest amount of chlorophyll a (19/75 µg/ml), chlorophyll b (4/63 µg/ml), total chlorophyll (25/27 µg/ml), and the total amount of pigments (27/67 µg/ml) were obtained by leaves foliar spray and drip treatment with the concentration of 400 mg/lit, drip treatment with 200 mg/lit condensation, and foliar spray and drip treatment with the distribution of 200 mg/lit. According to the results, the use of GA3 hormone causes an increase in the number of fruits, pigment performances, and reducing sugars in a ‎Jerusalem cherry. The methods used in GA3 consumption as a hybrid application leaves foliar spray plus soil application compared to drip treatment and foliar spray individually, showing better results. Therefore, the simultaneous foliar + drip treatment method is recommended as a suitable method for using GA3 to improve the appearance and photochemistry characteristics of a Jerusalem cherry.

Heavy metals pose a serious threat to environment and show adverse effects on plants, animals, and human health. Cadmium is one of the highly persistent toxic metals present in agricultural fields due to its excessive release through industrial and anthropogenic activities. The present paper deals with the effect of sodium selenate on the growth and physiological parameters of Pisum sativum L. grown under cadmium stress. The application of sodium selenate significantly enhanced root and shoot length, biomass, and physiological attributes such as chlorophyll, sugar, proline, protein, and total antioxidant contents in pea plants, protecting them against cadmium toxicity. The highest total antioxidant content (54%) was reported in Cd (20 mM) + SS (5 μM) treatment. Hence, the application of sodium selenate can be used as plant growth promoter for the growth of pea plants under cadmium stress.

Cadmium is a heavy metal with high toxicity that causes to oxidative stress in the plants and animals.The heavy metal stress tolerance in the plants with increasing content of reactiveoxygen species (ROS)require to use antioxidative pathways. Hydroponic experiments were performed with thirteen treatments consisting of a control (neither CdSO4 nor ameliorative factor CaSiO3 and SNP), CdSO4 at 25, 50, 75 and l00 µM concentrations without or with 1.5 mM ameliorative factor SNP or CaSiO3. The desired samples of leaves from 60-days-old plant used for determination activities of ascorbate peroxidase, peroxidase and polyphenol oxidas enzymes and content of chlorophyll a, chlorophyllb, totalchlorophyll, carotenoids, MDA, and proline. The obtained results were indicated that Cadmium decreased chlorophyll a, b, total chlorophyll and carotenoids contents significantly and ascorbate peroxidase, peroxidase, and polyphenol oxidase activities which were increased specially by adding CaSiO3. However, polyphenol oxidase activity increased under Cd stress significantly, which increased with adding ameliorative factor,CaSiO3.The MDA and proline content increased under Cd stress significantly, which decreased by adding ameliorative factors especially CaSiO3. It can be concluding that silicate effects that enhanced the Cd tolerance in Triticum aestivum L. is attribute to the silicate ameliorative effects–suppressed CdSO4 uptake and root to shoot CdSO4 transport. In addition, the silicate ameliorative effects are enhanced the antioxidant defenseactivity.

The true halophyte, Suaeda maritima is growing naturally at the Mediterranean coast. Terminal shoots and roots of S. maritima and its associated soil were taken from two sites across the Damietta- Port Said coastal road, Egypt through winter and summer, 2019. Soil physical and chemical properties were investigated in details. In addition to heavy metals, water content, phenols content, total ash, Na, K, Ca, Mg, and Cl were determined in both shoots and roots. Also, translocation factor and bioconcentration factor for heavy metals were assessed. Soil near the S. maritima rhizosphere was highly saline and had lower concentration of most metals (Al, Ba, Cd, Cu, Fe, Mo, Pb, Si) and total heavy metals during summer. The heavy metals were highly intake by roots and more sequestered in shoots and roots in summer. Water content and ash content were higher in winter season while the reverse was observed in total phenols and Na in both shoots and roots. Ca content accumulated highest at site 2 during summer for shoots and those growing at site 1 for roots either in winter or summer. Concerning Mg, the maximum value was recorded in plants at site 1 through summer in shoots and roots. Cl content was the greatest accumulation in S. maritima at site 1 through summer in shoots and those at site 2 in winter for roots.

Phalaenopsis orchid has high economic value in the floriculture industry and is one of the most popular orchids in the world. Tissue culture techniques makes it possible to propagate and conserve this species. The aim of the present study was to evaluate the effect of different concentrations of two plant growth regulators (PGRs), namely N-Phenyl-N′-1,2,3-thiadiazol-5-yl-urea (TDZ) and 2,4-dichlorophenoxyacetic acid (2,4-D), alone and in combination with each other, on the number of protocorm-like bodies (PLBs), leaves, and roots, along with leaf and root lengths of micropropagated Phalaenopsis circus using leaf explants through organogenesis method. Also, correlations between these traits in the Phalaenopsis circus plantlets under study were calculated. Plantlets produced from PLBs were cultured on MS (Murashige and Skoog) basal media enriched with various levels and combinations of TDZ and 2,4-D. The optimal concentrations of the PGRs for micropropagation of Phalaenopsis circus are reported and discussed. The maximum number of PLBs (75.00) was obtained on the medium enriched with 1.00 mg l–1 2,4-D. The highest length of leaf (5.23 cm) was calculated on the medium enriched with 2.00 mg l–1 2,4-D. Concentration of 1.00 mg l–1 TDZ induced the maximum number (6.07) of leaf. The longest root length (4.15 cm) and the largest number of root (4.93) was obtained in medium augmented with 2.00 mg l–1 2,4-D.

Centaurea hyrcanica is a kind of wheat flower. It is distributed in North and North-East of Iran. This study aimed to determine chemical composition of essential oil of C. hyrcanica for food supply, cosmetics-health industry and medicinal uses. The plant parts of C. hyrcanica were collected at flowering stage from four localities in Mazandaran, Tehran and Semnan Provinces in May and June 2016. The plant parts including of stem plus the leaf [SL], inflorescence IF and root R were dried and crushed in laboratory. The essential oils were obtained by hydrodistillation and were analyzed by gas chromatography (GC) and gas chromatography –mass spectrometry (GC/MS). The essential oils yield of stem plus the leaf, inflorescence and root (w/w dried weight) from different localities varied in range of 0.03-0.14%, 0.03-0.28% and 0.02 -0.77%, respectively. The major constituents of essential oils obtained from different parts of C. hyrcanica populations were caryophyllene oxide (13.6-44.8%) and spathulenol (3.6-16.9%). The major constituent of only root essential oils was found cis-pinane (9.1%-24.2%). Ethyl tetradecanoate (≤18.8%) as a major constituent in different populations of C. hyrcanica except Pol sefid samples. 1-Hexadecene, -eudesmol, -eudesmol and borneol were major compounds in essential oils of Pol sefid samples. Results of this study suggest that growing of C. hyrcanica in highlands condition is rich in essential oil and aroma profile, therefore growing and cultivation of these plants in cold regions is appropriate for producing high economic amount of extracted essential oil and aroma profile for therapeutic uses and food technologists.

Physio-biochemical changes in plants is a principal practice to manage harvesting time. The present study was aimed to investigate the effect of flowering stages (10%, 50%, and 100% flowering) on physiological and biochemical properties in four cultivars (Fasta, Hamadani, Meldor, and Sovrana) of third and fourth-year-old plants of Alfalfa (Medicago sativa L.) based on completely randomized design (CRD). The results showed that total phenolic content (TPC) and total flavonoid content (TFC) in Hamadani cultivar at middle flowering stages in fourth-year-old plants showed higher TPC and TFC. The catalase (CAT) and superoxide dismutase (SOD) activities increased by progressing the flowering stage and time of harvesting. Proline content increased by advancing the flowering stage as its highest amount was observed at late flowering stage in Fasta cultivar. Middle flowering stage represented the greater chlorophyll (Chl.) compared with other stages. Relative water content (RWC) decreased by progressing the maturity as its highest amount was observed at early flowering stage. RWC differed from 65% in fourth-year plants of sovrana at late flowering stage to 80% in third-year plants of Meldor at early flowering stage. Malondialdehyde (MDA) content and total soluble sugar (TSS) increased by advancing the maturity. Sovrana at late flowering stage and fourth year represented the higher MDA and TSS. Heat map analysis showed the significant role of all physiological and biochemical traits except total Chl. for clustering the cultivars. This work suggests the Hamadani cultivar because of high phenolic compounds and the minimum variation of their biochemical properties in the fourth year.